639773 has 4 divisors (see below), whose sum is σ = 641568. Its totient is φ = 637980.

The previous prime is 639757. The next prime is 639833. The reversal of 639773 is 377936.

639773 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 639773 - 2⁴ = 639757 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 639773.

It is not an unprimeable number, because it can be changed into a prime (639703) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 161 + ... + 1142.

It is an arithmetic number, because the mean of its divisors is an integer number (160392).

2⁶³⁹⁷⁷³ is an apocalyptic number.

It is an amenable number.

639773 is a deficient number, since it is larger than the sum of its proper divisors (1795).

639773 is a wasteful number, since it uses less digits than its factorization.

639773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1794.

The product of its digits is 23814, while the sum is 35.

The square root of 639773 is about 799.8581124174. The cubic root of 639773 is about 86.1671977157.

The spelling of 639773 in words is "six hundred thirty-nine thousand, seven hundred seventy-three".